The present invention relates in general to flat panel displays, and in particular to spacers for spacing apart panels in flat panel displays.
A conventional flat panel display 10 shown in FIG. 1 is useful in a portable device, such as a notebook computer 12, that requires a thin display having less weight and power consumption than a cathode ray tube (CRT) display. Typical well-known flat panel displays are field emission displays, passive and active matrix liquid crystal displays, and plasma displays.
As shown in FIG. 2 in a cut-away view, a conventional flat panel display 10 generally includes a transparent face panel 14 spaced apart from a base panel 16. In a field emission display, the face and base panels 14 and 16 are spaced apart from one another to create a space which can be evacuated so electrons will be emitted from emitters (not shown) in the base panel 16. Also, in a liquid crystal display, the face and base panels 14 and 16 are spaced apart to create a space for liquid crystal cells, and in a plasma display the face and base panels 14 and 16 are spaced apart to create a space which can be filled with a gas for generating plasma.
The face panel 14 and base panel 16 are typically spaced apart from one another by thousands of columnar spacers 18 individually formed or positioned between the panels 14 and 16. Because the columnar spacers 18 must be individually formed or positioned, the flat panel display 10 can be difficult, time-consuming and costly to manufacture. Also, the columnar spacers 18 cannot be positioned accurately enough to ensure that they do not interfere with an image generating apparatus (not shown) in the flat panel display 10. As a result, it is sometimes necessary to scrap the flat panel display 10 after manufacturing if its display image 20 is substantially affected by interference from the columnar spacers 18. Further, the columnar spacers 18 are generally limited to about 100 xcexcm in height because they are unstable above that height. As a result, the brightness of field emission displays is limited, because the limited height of the columnar spacers 18 limits the distance between the face and base panels 14 and 16 which, in turn, limits a voltage differential between the panels 14 and 16. The limited voltage differential limits the brightness of the field emission displays.
Therefore, there is a need in the art for an improved structure for spacing apart the face and base panels in flat panel displays. The structure should be simple to manufacture, easy to align with the image generating apparatus in a flat panel display, and capable of exceeding 100 xcexcm in height to help increase the brightness of field emission displays.
An inventive spacing structure is a unitary structure of uniform height which projects between a flat panel display""s face and base panels across a substantial area of their facing surfaces. As a result, the unitary spacing structure spaces a substantial portion of the face panel away from the base panel in a substantially parallel spaced apart relationship with the base panel. Preferably, the unitary spacing structure includes a multitude of rail members framed by and interconnected with a multitude of frame members. Because the inventive spacing structure is a unitary structure, it can be conveniently manufactured apart from the flat panel display and then easily aligned with the image generating apparatus of the display. Thus, the unitary spacing structure can help to make flat panel displays less difficult, time-consuming and costly to manufacture. Also, the rail members and frame members of the preferred unitary spacing structure make the structure stronger than conventional columnar spacers because the rails distribute the force they support. As a result, the unitary spacing structure can easily exceed 100 xcexcm in height and can thereby help increase the brightness of field emission displays.